Fluid-pressure brake.



No. 722,128. PATENTED MAR. 3, 1903.

' M. MOOOMAS- FLUID PRESSURE BRAKE.

APPLICATION FILED DEC. 31, 1901.

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No. 722,128. PATENTED MAR. 3, 1903.

M. MQGOMAS. I

FLUID PRESSURE BRAKE.

APPLICATION FILED DEC. 31, 1901.

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MARK MCCOMAS, OF GREENVILLE, TEXAS.

FLUID-PRESSURE BRAKE.

SPECIFICATION forming part of Letters Patent N 0. 722,128, dated March 3, 1903. Application filed December 31, 1901. Serial No. 87,979. (No model.)

To (tZZ whom it may concern:

Be it known that I, MARK MCCOMAS, a citizen of the United States, residing at Greenville, in the county of Hunt and State of Texas, have invented new and useful Improvements in Fluid Pressure Brakes, of which the following is a specification.

My invention has relation to new and useful improvements in fluid-pressure brakes particularly adapted for use on railwaytrains; and the object of the invention is to provide a simple, durable, and efficient device for controlling the exhaust of fluid under pressure from the brake-cylinder, and thereby preventing such exhaust when the auxiliary pressure is reduced below a predetermined degree and allowing the restoration of the auxiliary-reservoir pressure without the necessity of releasing the brakes.

A further object of the invention is to produce a device which will prevent the prema ture release of the brakes before the auxiliary reservoir has been recharged.

The invention consists in the improved ar rangement of the various elements comprising the device and their aggroupment in operative combination, to be more fully described hereinafter and the novelty of which will be particularly pointed out and distinctly claimed.

I have fully and clearly illustrated my invention in the accompanying drawings, wherein Figure 1 is a side elevation of a fluid-pressure brake system in connection with which my invention is employed. Fig. 2 is an enlarged vertical longitudinal sectional view of the device, and Fig. 3 is a bottom plan view of the invention.

Referring to the drawings, 1 designates a portion of a train-pipe, which is connected in any approved manner to a suitable source of supply and from which projects a branch pipe 2, which is in turn coupled to a triple valve 3, having communication with an auxiliary reservoir 4: and the brake-cylinder 5.

The construction and arrangement of the system just described are practically the same as the Westinghouse form of brake mechanism and needs no further description.

In carrying out my invention I connect a pipe 6 to the exhaust-port 7 of the triple valve 3 and to the exhaust-controlling device,which is secured to the auxiliary reservoir of the fluid-pressure system in any suitable manner.

The exhaust-controlling device above referred to and which embodies my invention I designate by the numeral 8. This device comprises a central cylindrical casing 9, the upper portion of which is provided with an annular shoulder 9 and an annular interiorlythreaded flange 9", which flange and shoulder are adapted to be engaged by a depending or exteriorly threaded flange a, formed on a cap (2, whereby the top portion of the casing'9 is closed. The bottom portion of the casing is also provided with a flange 9, which is similar to the flange 9 and is adapted to receive a vertical exteriorlythreaded flange 9 formed on the lower tubular casing 22.

The cylindrical casing 9 is divided into up per and lower chambers (designated by 10 and 11, respectively) through the medium of a valve 12, which is adapted to be seated upon a valve-seat 13, arranged intermediate the casing and above the valve 12. Projecting upwardly from the top face of the valve 12 is a vertical stem 14, the extreme upper end of which terminates in a threaded shank '14 for the purpose hereinafter described.

Resting upon the shoulder 9 of the cylin- I .formed with a central threaded aperture adapted to receive the shank 14c on the stem of the valve, whereby the said diaphragm and valve are operativelycoupled. To insure against the displacement of the nut from its position within the diaphragm, a pin 30 is inserted through the flange 28 of the nut and shank, substantially as shown in the drawings.

From the under face of the valve 12 projects a depending stem 18, which is formed with a reduced portion 19, which forms a shoulder 20, against which bears a spring 21, located within the tubular portion 22 of the casing above referred to. At its lower end the interior of the portion 22 is threaded, as at 22 and engaging the said threads and extending up within the interior of the casing is an interiorly-threaded adjusting-nut 31, the upper face of which bears against the spring 21, whereby the tension of the said spring may be regulated. The nut 31 is securely held in position by means of a jamnut 32, which is threaded upon the nut 31 and engages the lower end of the spring-casing. Of course it will be obvious that the degree of resistance accorded by the valve will be regulated by the predetermined amount of pressure from the brake mechanism.

It will be noticed that the pipe 6 is connected to the casing 9 through a threaded inletport 25, positioned intermediate the valve 12 and the diaphragm 28, while the entire device 8 is connected to the auxiliary reservoir through the medium of a threaded neck 26, having a central passage or port 27 therein, which communicates with the chamber 10, as will be presently explained.

In one side of the casing 22 is formed a port 33 for the escape of the air within the same, and on the side of the case 9, containing the valve and the diaphragm, is an exhaust-valve 34, whereby pressure between the diaphragm and valve may be relieved.

The operation of the device is as follows: When the auxiliary cylinder is being charged, the fluid under pressure enters the device through the neck 26, and upon the pressure becoming sufficiently high to overcome the spring the valve is moved toward the spring, thereby permitting the air to pass out through perforations 17, forming the exhausts. This position of the valve is maintained so long as the auxiliary cylinder is charged. When the brakes are applied, the pressure is reduced in the auxiliary cylinder and the air will flow out of the port 27 until the pressure that forces the valve in the position above described is equal with that in the auxiliary cylinder. When the pressure is reduced sufficiently to be overcome by the spring 21, the diaphragm and Valve 12 will move toward the auxiliary cylinder until the valve is seated on the seat 13. However, when the pistons of the triple valve are moved to released position by increase of train-pipe pressure air will pass through the exhaust to the triple valve and into the device 8 and will be detained by the valve being seated at 13. It will be held in this position until such time as the auxiliary pressure is great enough to iary reservoir, an inlet for the exhaust from the triple mechanism, and a relief-valve, said casing being provided with a valve-seat dividing it into upper and lower chambers, the lower of which is provided with exhaust-ports, of a valve intermediate the said chambers and held normally unseated, said valve having a vertically-extending stem having a threaded portion, and a depending stem having a reduced portion to form a shoulder, a spring surrounding the reduced portion and bearing against the shoulder, a nut for controlling the tension of the spring, adiaphragm mounted inthe upper chamber and having a coniral aperture, and an interiorly-threaded nut secured in said aperture to receive the threaded stem on the valve.

2. In a safety device for fluid-pressure brakes, the combination with a casing having an inlet-port communicating with the auxiliary reservoir, an inlet for the exhaust from the triple mechanism, and a relief-valve, said casing being provided with a valve-seat dividing it into upper and lower chambers, the lower of which is provided with exhaust-ports, of a valve intermediate the said chambers, said valve having a vertically-extending stem, and a depending stem having a reduced portion to form a shoulder, a spring surrounding the reduced portion and bearing against the shoulder, a nut for controlling the tension of the spring and a diaphragm in the upper chamber, said diaphragm being secured to the vertical stem on the valve.

In testimony whereof I affix my signature in presence of two witnesses.

MARK MOCOMAS.

Witnesses:

O. B. JONES, J. G. ROBINSON.

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